1. Field of the Disclosure
The present disclosure relates to electronic devices, in general, and more particularly to a method for supplying power and an electronic device performing the method.
2. Description of Related Art
With the development of mobile communication technology and processor technology, according to user demand for something new and different, mobile electronic devices have been evolved to be equipped with new and different functions. In order to allow users to use functions or additional functions of a mobile electronic device more conveniently, external devices configured to connect to the mobile electronic device are required. To this end, various technologies have been proposed and commercialized to connect between mobile electronic devices and external devices, e.g., a mouse device, a keyboard, an external storage device, a wired LAN, High Definition Multimedia Interface (HDMI), a multimedia dock, Head-mounted display (HMD), etc. For connection with external devices, mobile electronic devices have supported standardized interface such as Universal Serial Bus (USB), etc. In addition to USB, mobile electronic devices have been internally equipped with an additional interface to perform data communication with external devices.
Mobile electronic devices with a USB connector allow various external devices (or accessories) to be attached thereto in On-The-Go (OTG), thereby use functions of the external devices. On-The-Go (OTG) is a USB specification supporting USB communication between mobile electronic devices such as smartphones, tablet personal computers (PCs), etc. or between a mobile electronic device and its peripheral such as a mouse device, a keyboard, a USB memory, etc., without the use of a personal computer (PC). In recent years, external devices capable of connecting to a mobile electronic device via OTG have increased in variety. For example, an OTG hub has been developed, allowing a number of external devices to be attached to one mobile electronic device.
A mobile electronic device and an external device are connected to a USB connector of the mobile electronic device. Since an external device connected to a mobile electronic device via OTG (where the external device is hereafter called an OTG device) is not equipped with a separate power source, it receives its operating power from the mobile electronic device via the USB connector of the mobile electronic device. When a mobile electronic device detects the OTG connection of an external device, its internal power control module activates a reverse boost function to adjust (step up or down) the output power of the battery to a preset level in order to supply the adjusted power to the OTG device.
When a mobile electronic device with an OTG device connected thereto is running, it needs to supply power from the battery to the OTG device and increases in its level of power consumption. In order to reduce power consumption in the mobile electronic device with an OTG device, it frequently uses an external power supply, e.g., Travel Adapter (TA). In this case, the mobile electronic device supplies power from the external power supply to the OTG device and also charges the charge module with power received via the connector from the external power supply.
As described above, when a mobile electronic device is connected to an OTG device and an external power supply, the conventional system supplies power from the external power supply to the OTG device but does not need to supply power from the mobile electronic device to the OTG device. Therefore, the conventional system blocks power supplied from the built-in battery of the mobile electronic device to the OTG device via the connector.
When the external power supply is removed from the mobile electronic device with the OTG device attached thereto, the OTG device inevitably experiences a temporary interruption of the supply of power thereto. That is, although the mobile electronic device detects the removal of the external power supply and activates the reverse boost function, it will take a period of time (e.g., tens of milliseconds) to supply power to the OTG device from the disconnection with the external power supply, so disconnection with the OTG device may occur. In this case, it may take a few seconds until the OTG device is reset and re-connected to the mobile electronic device.
Therefore, a system is required to resolve these problems and maintain the connection between the OTG device and the mobile electronic device, regardless of connection or disconnection with an external power supply.
The foregoing description of related art is merely intended to provide a better understanding of the background of the disclosure. Therefore, it should not be understood that the technology in the description of related art has already well-known to those skilled in the art.